Latin name: Polemonium reptans. 
Variety denomination: xe2x80x98Stairway to Heavenxe2x80x99.
The present invention relates to a new distinctive cultivar of a hardy perennial herabaceous plant of the genus Polemonium, a member of the Polemoniaceae family, and the species reptans, known by the cultivar name xe2x80x98Stairway to Heavenxe2x80x99. The species is commonly known and referred to by the commercial designation xe2x80x9cSpreading Jacob""s Ladderxe2x80x9d.
The new variety was discovered at a nursery in Framingham, Mass., as a naturally occurring seedling (whole plant) mutation of the species Polemonium reptans. The Polemonium reptans seedling named xe2x80x98Stairway to Heavenxe2x80x99 came up variegated from seed collected from typical Polemonium reptans var. reptans growing in the nursery and has remained stable through four successive years of evaluation. The new cultivar xe2x80x98Stairway to Heavenxe2x80x99 is quite distinct from typical plants of Polemonium reptans var. reptans known to me and was discovered primarily due to its unique white and light green foliar variegation. During the winter, small, predominantly pink leaves cluster at soil level at the tips of active rhizomes.
Asexual reproduction of the new cultivar by tissue culture (micropropagation of rhizome buds) and by division of the rhizome and roots in Eastford and Kingston Conn., has shown that the unique features of the new Polemonium are firmly fixed and retained through successive generations of asexual reproduction. In other words, the new cultivar reproduces true to type in successive generations of asexual reproduction.
The new cultivar xe2x80x98Stairway to Heavenxe2x80x99 is particularly characterized by its variegated foliage which to the best knowledge of the inventor, is unique for the species. The parental (seed and pollen) parents exhibited non-variegated leaves of a uniform medium green (Pantone 575U) that is typical for the species Polemonium reptans var. reptans. Plants of the species, including the new cultivar, thrive best in moist, fertile soil and full sun to light shade.
The habit of the plant is a clumping perenial with a mount of basal leaves and branching stems with small cauline leaves and flowers in branched panicles. The leaves of xe2x80x98Stairway to Heavenxe2x80x99 are once odd-pinnately copound, with from 5 to 17 leaflets per leaf, averaging 13-15 on a typical basal leaf and 3-7 on upper cauline leaves. A few of the smallest leaves subtending the flowers may be simple. The leaflets have no petiolule, so are therefore sessile to the rachis. The leaf base is rounded on a typical leaflet but some leaflets have more of an acute base. The margin is entire. The rachis and petiole is a combination of Pantone 575 U, 5767U and 461C arranged in bands along the rachis and petiole bleeding into a deep purple red (Pantone 234U) toward the base of the petiole especially in colder weather.
The main foliage color is medium green but there is on the upper and lower surfaces of each leaflet either a smooth or ragged marginal band of creamy white (Pantone 461C) that extends xe2x85x9th to xc2xd of the way to the midvein. The center of a typical leaflet""s upper surface is medium green (Pantone 575U), and at the location where the white and green meet, there is an irregular band of pale gray-green produced from a blending of the others (mix of Pantone 5767U and 5797U). The relative amount and distribution of the three colors (white, gray-green, and medium green) varies from leaflet to leaflet and from leaf to leaf. In general, the immature leaves have more marginal white banding, while on older and dehiscing leaves, the white changes to a shade darker creamy white (Pantone 460C). Some leaflets are all white or white with a thin pocket of green or gray-green toward the center. The white areas of immature, expanding leaves taken on a light pink tone (Pantone 230U) if grown in bright light or cool weather ( less than 70 degrees F.), but the pink fades as the leaf becomes fully expanded and/or the weather warms. The lower leaf surface is a combination of a marginal band of creamy white (Pantone 461C) and a central patch of gray green (mix of Pantone 5767U and 5797U).
xe2x80x98Stairway to Heavenxe2x80x99 has five sepals having a color of medium green (Pantone 575 U) fused along the lower half into a bell shape. The base of the bell is rounded and is 2 mm wide. The upper half or each sepal lobe has an elliptical shape with an acute tip. The total sepal length is 5 mm. The width of each individual sepal lobe at the widest point is 2 mm. The width of the calyx at the widest point is 6 mm.
Flower color is identical with the parental species, violet blue on both the upper and lower surfaces of the petals (Pantone 263U). Flowers are campanulate, 2 cm long and 16 mm wide, with a slight sweet fragrance. The corolla consists of five petals fused along the lower half into a narrow bell (3 mm at the base). The upper (free) half of each petal is oval with a rounded tip. Petal length from the base of the corolla to its tip is 2 cm. Individual petal width at its widest point is 6 mm. The pedicle length is 5-8 mm with a diameter of 1 mm and the coloration is medium green (Pantone 575U). Each flower has five stamens each about 2 cm from base to tip, and one e cm from base to tip, and one exerted pistil with 3 stigmatic lobes. The pistil is 24 cm long from base to tip. The ovary is superior and divided into three locules, each containing from 1-10 ovules. Fruits is an oval, tri-locular capsule with a rounded base and acute tip produced in, and partially enclosed by, the cup formed by the calyx. Mature fruit dimensions are 6-7 mm long and 4 mm wide at the widest point. The color of the fruit is medium green (Pantone 575U). Mature seeds are crescent shaped, 3 mm long and 1 mm wide in the middle, narrowing abruptly to an acute tip at both ends. Ripe seed is dark brown (Pantone 497C), rough in texture (under magnification), with a sunken pit (0.5 mm wide) on one side toward the center of the seed.
xe2x80x98Stairway to Heavenxe2x80x99 has naked vegatative buds (no bud scales evident), the winter buds lie in groves along a creeping rhizome. The buds are 1-2 mm in diameter and length, ovoid in shape and develop deep red-purple coloration (Pantone 234U) during winter dormancy. During active growth, buds are obscured by the foliage.
In addition to the described comparison with typical plants of the species, including the parent cultivar, xe2x80x98Stairway to Heavenxe2x80x99 can be compared with the Polemonium reptans cultivar xe2x80x98Albumxe2x80x99 (unpatented) which has white flowers and non-variegated foliage, and xe2x80x98Blue Pearlxe2x80x99 (unpatented) which is also non-variegated and has dark, blue-violet flowers. Additionally, xe2x80x98Blue Pearlxe2x80x99 has a very different habit than xe2x80x98Stairway to Heavenxe2x80x99. The xe2x80x98Blue Pearlxe2x80x99 is taller (24-28 inches), and the stem and leaves are stiffer.
The cultivar xe2x80x98Stairway to Heavenxe2x80x99 has not been observed under all possible environmental conditions. The phenotype may vary somewhat with variations in environment such as temperature and light intensity without any variance in genotype. The following observations, measurements and comparisons describe a four year and three month old plant grown in Framingham, Mass. under conditions which closely approximate those generally used in commercial practice. xe2x80x98Stairway to Heavenxe2x80x99 has not been found to suffer from any particular disease or insect pest under cultivation in Framingham, Mass.
The following traits have been repeatedly observed and are determined to be the distinctive and unique characteristics of xe2x80x98Stairway to Heavenxe2x80x99. These characteristics in combination distinguish xe2x80x98Stairway to Heavenxe2x80x99 as a new and distinct cultivae.